Routine office visits accounted for the single largest share of Medicare physician billings in 2012 even though they amounted to just one one-seventh of the $77 billion paid by the government for physician services through the nation’s senior citizens healthcare program.

The data, released Tuesday, comes from the first-ever publication of Medicare Part B payments to individual physicians and physician practices by the CMS. The agency released the data in response to demands for transparency in the wake of court case requiring the agency to provide public access to physician billing records.

The database includes 9.2 million lines describing transactions worth $77 billion by 880,000 physicians and physician practices certified to collect from Medicare. The data include physicians' names and office locations, the exact services for which they billed Medicare, the average payments for each service and the number of patients who received each service.